Я приложил карту к валидатору, но он не сработал с первого раза.

Приложил is the perfective past form of приложить, so it presents the action as a completed single event: the speaker tapped/placed the card once.

If you said я прикладывал карту, that would usually sound more like:

• a repeated action,
• an attempted action,
• or a process without focus on completion.

In this sentence, the speaker is describing one finished action in a sequence:

1. I tapped the card
2. but the validator didn’t work the first time

So приложил is the natural choice.

In the past tense, Russian verbs agree with the speaker’s gender in the singular:

• приложил = masculine speaker
• приложила = feminine speaker
• приложило = neuter
• приложили = plural

So this sentence suggests the speaker is male, or the example is just using the masculine default form.

Because карта is the direct object of приложил.

The verb приложить here means to place/tap something against something, and the thing being placed is in the accusative case:

• nominative: карта
• accusative: карту

Since карта is a feminine noun ending in -а, its accusative singular changes to -у.

The preposition к normally means to, toward, up to and requires the dative case.

So:

• валидатор = nominative
• к валидатору = dative after к

In this sentence, приложить что-то к чему-то is a common pattern:

• приложить карту к валидатору
• literally: to place the card to/against the validator
• naturally: to tap the card on the validator

Literally, приложить что-то к чему-то means to place something against something.

In transport/payment contexts, it is commonly used for:

• tapping a card,
• holding a phone to a reader,
• placing a pass against a scanner.

So while the literal image is placing the card against the validator, the natural English translation is often:

• I tapped my card on the validator
• I held my card up to the validator

Grammatically, он is masculine singular, so it can only refer to a masculine noun.

In this sentence:

• карта is feminine, so он cannot refer to the card.
• валидатор is masculine, so он refers to the validator.

So но он не сработал means but it (the validator) didn’t work.

Russian often uses pronouns the same way English does to avoid repetition.

So instead of:

• ..., но валидатор не сработал ...

it says:

• ..., но он не сработал ...

This sounds natural and avoids repeating the noun. Since карта and валидатор have different genders, the pronoun is also clear here.

Сработал is the perfective past form of сработать.

This verb can mean different things depending on context, such as:

• to work
• to go off
• to trigger
• to function successfully

Here it means something like:

• didn’t work
• didn’t register
• didn’t respond properly

With a validator, не сработал usually means the machine did not successfully read/accept the card on that attempt.

Good question. These are similar, but not identical.

• не работал = was not working / wasn’t functioning
• не сработал = didn’t work (on that occasion) / didn’t trigger/respond successfully

In this sentence, the speaker is talking about one specific attempt, so не сработал is better. It focuses on the result of that single event.

Compare:

• Валидатор не работал весь день. = The validator wasn’t working all day.
• Я приложил карту, но валидатор не сработал. = I tapped the card, but the validator didn’t work/respond.

С первого раза is a very common Russian expression meaning:

• on the first try
• the first time
• at the first attempt

Literally, it is something like from the first time/attempt, but idiomatically it means immediately on the first attempt.

Examples:

• Я понял не с первого раза. = I didn’t understand the first time.
• Дверь открылась с первого раза. = The door opened on the first try.

So не сработал с первого раза means:

• didn’t work the first time
• didn’t register on the first try

Because но means but, and it joins two clauses:

• Я приложил карту к валидатору
• он не сработал с первого раза

In Russian, a comma is normally used before coordinating conjunctions like но when they connect two separate clauses.

So the comma here is standard punctuation.

The word order is natural, but Russian is fairly flexible.

The given sentence:

• Я приложил карту к валидатору, но он не сработал с первого раза.

is neutral and clear.

You could change the order slightly for emphasis, for example:

• Я приложил карту к валидатору, но с первого раза он не сработал.
• К валидатору я приложил карту, но он не сработал с первого раза.

These alternatives are possible, but the original sounds the most straightforward in everyday speech.

Yes. In real usage, валидатор не сработал is very natural even if, logically, the issue could be with the card, the sensor, or the system.

Russian often describes this kind of situation from the point of view of the device failing to respond properly. So the sentence does not necessarily mean the machine was broken; it can simply mean:

• it didn’t read the card,
• it didn’t react,
• it didn’t accept the tap on the first attempt.

So it is idiomatic, not overly literal.

Only the first past-tense verb would change:

• Я приложила карту к валидатору, но он не сработал с первого раза.

Why only that one?

• приложила agrees with the female speaker.
• сработал still agrees with он = валидатор, which is masculine.

So:

• female speaker: приложила
• masculine noun валидатор: сработал